Temporal Bone Osteoradionecrosis after External Beam Radiation Therapy for Head and Neck Cancer

Abstract

Objectives: Radiation therapy (RT) for head and neck cancer (HNC) may be associated with osteoradionecrosis of the temporal bone (ORN-TB). The goal of this study is to examine the incidence of ORN-TB in HNC patients receiving RT ± chemotherapy (chemo) and its association with patient- and treatment-related factors. Methods: Pre- and post-RT records of 376 HNC patients were retrospectively assessed for the presence of possible ORN-TB. Dose received by tympanic ring was estimated using the computed tomography-based treatment plan for the patient. Uni- and multivariate analyses evaluated the association between various variables and incidence of ORN-TB. Results: ORN-TB was diagnosed in 27 (7.2%) patients over a median time of 9.5 years (range, 1-17 years). Of these, localized ORN-TB was observed in 18 (66.6%) patients, diffuse ORN-TB in 9 (33.3%) patients. Dose received by temporal bone ranged from 35 to 80 Gy. RT dose was significantly associated with ORN-TB ( P = .015) and adjuvant chemo ( P = .045), but age (>60), gender, and fractionation were not. Conclusion: RT dose appears to be the primary determinant of ORN-TB in HNC patients. Further prospective investigation is needed to better understand the factors that might contribute to and protect from ORN-TB.